Key-lever tension device



O. A. HOKANSON.

KEY LEVER TENSION DEVICE.

APPLICATION FILED JUNE 3. 1918.

1,375,789. Patented Apr.26,19,21.

2 SHEETS---SHEET1.

UNITED STATES PATENT OFFICE.

OTTO A. EOKANSON, OF WOODSTOCK, ILLINOIS, ASSIGNOR T WOODSTOCK TYPE- WRITER COMPANY, OF WOODSTOCK, ILLINOIS, A CORPORATION OF ILLINOIS.

KEY-LEVER TENSION DEVICE.

Specification of Letters Patent.

Application filed June 3, 1918. Serial No. 237,934.

2 '0 all whom it may concern:

as or the several key levers, but it is found indifferent typewriter operator's.

Be it known that I, Orro A. HOKANSON, a'citizen of the United States, residing at Woodstock, in the county'of McHenry and State of Illinois, have invented certain new and useful Improvements in Key Lever Tension Devices, of which the following is a specification.

This invention relates to typewriters, and more particularly to the means for varying the tension which is placed upon the key levers of a typewriter.

The principal object of the invention isto provide a new and improved construction by means of which the spring pressure which opposes the movement of the typewriter key levers can be varied to meet various conditions of touch and operation, to quicken the return of the type bars, and prevent them from colliding.

The invention consists in the novel 'construction, combination and arrangement of the parts.

In the accompanying drawings- Figure 1 is a side elevation with parts shown in section of a key lever tensioning device constructed in accordance with the principles of this invention.

Fig. 2 is a view of the under side of a machine showing a portion of the mechanism.

vFig. 3 illustrates a modified form;

Fig. 4 is a View from the under side of a machine embodying the modified form; and

Fig. 5 is a detail of an eccentric adjusting screw.

Figs. 6 and 7 are'fragmentary views simi-- lar to the parts of Figs.-l and 3, respectively,

tion.

It is frequently necessary to vary the tension applied to the keylevers of a typewriter, and although each key lever usually.

has separate means for varying the tension of the spring which returns the key lever, it is also desirable that additional means he provided for changing the tension of all of the key levers for different conditions in writing, and to accommodate the touch of The individual adjustment of the key lever tension mechanism is usually made at the factory for the purpose of equalizing the actions showing a slight modification of the invenpractice'that it is necessary to provide an additional tensioning means which can be easilyapplied by any operator so that the machine will be satisfactory for that indivlduals touch. The present invention relates to the provision of such an additional tenslonmg device as applied to a typewriter.

At the rear of a typewriter frame 1- Patented Apr. 26, 1921.

ends of the key levers to prevent them from I being accidentally displaced from their piv-' otal mounting. The lower edge of each key lever is formed with a projection. 9 which seats one end of acoil spring 10, the other end of which engages a variable tensloning screw 11 threaded into the under side of the sub-frame 2, the spring tending to press the front end of the key lever upwardly. Near the front end of the key lever a transverse slotted comb 12 is secured to the frame for guiding this end of the key levers, and intermediate the ends of each key lever it is provided with a pin 13 which engages a slot in a pivoted type bar actuating lever 14. which is actuated in the well-known manner by the depression of the key lever.

Also mounted upon the pivot wire 5, at each end thereof, is an arm 15 which supports a universal bar 16 formed with separate tongues 17, each of which is adapted to be engaged by the lower edge of a key lever 6 in its downward movement, the tongues being bendable so that the engagement of the'key levers therewith can be varied to a certain extent to make up for variations in size and shape of the different parts. Attached to the outer side of the universal bar, adjacent the center thereof, is

Pivoted in a bracket 20 extending down-- wardly from the sub-frame 2, as shown in Figs. 1 and 2, is a shaft 21 to which for-- Wardly extending arms 22 are secured adjacent the end thereof, and a rearwardly extending arm 23 adjacent the center thereof. The forwardly extending arms 22 project just below the universal bar 16 which pro vided with contact buttons 2 l which are adapted to be engaged by the extremities of the arms 22 when the universal bar is moved downwardly a predetermined amount by the engagement of the key levers. The rearwardly extending arm 23 has a bent extremity 25 which normally rests upon a stop screw 26 threaded in the typewriter frame, and the arm is yieldingly held in this .position by means of a spring 27, one end of which engages the arm, and the other end of which is in engagement with an adjusting screw 28, which is threaded through the rear portion of the frame and is provided with a headior engagement by the lingers of an operator.

It will be obvious from this construction that the tension applied by the spring 27 to the arm 23 can be varied by the movement of the screw 28, thereby varying the spring tension and the amount oi opposition which will be offered to the movement at the uni' versal bar as soon as it engages the extremities of the arms 22. 1n order to hold the adjusting screw 28 in any position in which it is placed, a disk 29 of rubber, or the like, as shown in Fig. 3, is pressed against the 30, and in order to hold the key lever ten- 'sion screws 11 in their adjusted position, a

plate 31 with spring tongues 32 is held yieldingly against the screws.

In the form shown by Figs. 3, 4e and 5, the operating parts are substantially the same as shown in Fig. 1, but the universal bar 33 is mounted in arms 3i pivoted on a shaft 35 which is mounted in brackets 36. A single bracket 37 is attached to the cen' ter of the plate 8, and in this bracket a lever 38 is pivoted which has a bent extremity 39 engaging the stop screw 26, and at its other end it has a pin and slot connection with a link 40 which is pivotally connected to one of the arms 34 which supports the universal bar 33. This lever 38 is preferably mounted in the bracket 37 by means of an eccentric screw l1 which permits the pivot point of the lever to be varied as desired.

It will be seen that the action of the two devices is substantially the same, for the lever 38 will have no eil ect upon the universal bar 33 until the 'pin and slot connection between it and the link d0 is taken up which corresponds to the movement of the determined movement earnt ea universal bar 16 until it engages the extremities oi the arms 22. V

lit is contemplated that this construction may be used purely as an adjustable tensioning device tor the key levers, and in such a case the bracket 18 would be omitted from the universal bar 33, as well as the connecting link 19, and this ba1f33, as shown in lFig. (i, would then become simply a rail which would be engaged by each of the key levers upon their depression. For obtaining this result instead of the construction shown by Fig. 3, thelink 40 and the lever 38 would be connected simply by a pivot pin as shown tained in the construction shown by Figs. 1

and 2 it the bracket 18 and the link 19 are removed from the bar 16 allowing the contact buttons 24 to rest directly upon the tips of the arms 22 as shown in Fig. 7.

ll claim: v

1. ln a typewriter, a plurality of pivoted key levers, means tending normally to hold thein resiliently in place, a universal bar directly engaged by the key lever after a prethereof, a resilient means tending to oppose the movement of the universal bar after a predetermined movement thereof and means for regulating the tension of said resilient means to control,

the key lever tension of said typewriter.

2. 'lhe combination with a pivoted and spring pressed key lever, of a universal bar engaged by thekey lever alter a predetermined movement thereof, and resilient means comprising a spring-pressed lever spring tension means for the universal bar comprisin a lever pivoted intermediate its ends and having one end engaged by a stop in such position to hold the other end-at a distance spaced from the universal bar in thepath or movement thereof, and a spring tending normally to hold the lever against the said stop.

lln a key lever tensioning device for typewriters, a universal bar engaged and moved by each of the key levers, a lever pivoted intermediate its ends having one extremity thereof resiliently held in such position thatthe other end thereof is normally spaced from the universal bar but is in the path of movement thereof, and a friction button carried by the universal bar for engagement with the end of said lever.

5. The combination with a keylever and means for normally tensioning it, of a universal bar normally spaced, from but engaged by the key lever in its operative movement, an adjustable spring tension device comprlsmg a lever one extremity of whlch is normally spaced from the universal-barbut in the path of movement thereof,- a spring in engagement with the other end of the lever, and an adjusting screw for varying the tension of said spring.

6. The combination with a pivoted key" pivoted intermediate its ends, a stopfor one end of the lever, a spring of which one end engages the lever-for holding it against the stop, an adjusting screw for engaging the other endof the spring, and means for holding the adjusting screw in any set position,.

said means comprising a yielding disk and a set screw for presslng the disk against the threads of said adjusting screw.

:8. In a typewriter, a plurality of key I levers pivoted at their rear ends and each having a separately adjustable spring tensioning means, a universal bar having bendable tongues each engaged by one of the key levers when the key levers are operated, an additional tensionmg means -for the key levers comprising a lever pivoted intermediate its ends having a stop at one endfor holding theother' end of the lever normally at a distance from the universal bar, and adjustable spring tensioning means for holding the lever against the stop whereby a yieldingv oppositlon is offered to the move ment of the universal bar when it is moved 7 a predetermined distance by the engagement of anykey lever therewith.

' 9. In a key lever tensioning device for typewriters, a tensioning lever pivoted below the key levers, a stop for one end of the J against the-stop, a member extending transversely below, the key levers and adapted to be engaged by them upona predetermined downward movement, and means forming an engaging contact between said member and thetensioning lever to aid the tension of said springin opposing the downward movement of the key levers.

In testimony whereof I have signed my name to this specification on this'29th day of May AQ D. 1918.

OTTO HOKANSQN.

lever, a spring tending. to press the lever 

